This invention relates to the retention and support of pivotally connected slats forming a roll-up shutter such as a hurricane or storm shutter and of the general type disclosed in U.S. Pat. No. 5,839,493, the disclosure of which is herein incorporated by reference. The storm shutter slats are commonly made from an aluminum extrusion or an extrusion of rigid plastics material such as rigid polyvinylchloride (PVC), and each slat includes inner and outer arcuate side walls which are integrally connected by longitudinally extending internal webs and longitudinally extending edge walls. The opposite edge walls of each slat commonly form a longitudinally extending hook portion and an undercut cavity or recess which form pivotal connections between adjacent slats so that the connected slats may be rolled up into a coil as shown in the above '493 patent. Other forms of shutter slats and retention systems are disclosed in U.S. Pat. Nos. 5,253,694, 5,996,669, and published PCT patent application No. WO87/03641.
With any shutter assembly such as disclosed in the above mentioned patents, the opposite end portions of the pivotally connected horizontal slats are connected to and retained by generally vertical elongated metal side rails which are usually mounted on the window or door frame and guide the horizontal slats during vertical movement between the rolled-up retracted position and the lower extended and window covering position. With any such support and guide system for the slats, it has been found desirable to provide a high strength connection between each slat and the metal or aluminum side rails while also providing for smooth and low friction movement of the slats without producing wear of the side rails or the retention system. When a storm shutter is used for resisting very high or hurricane wind forces and/or very high impacts, it is also desirable for the slat retention system not to damage the side rails or slats or retention system while resisting the wind forces or impacts. If the side rails or retention system are damaged, the shutter system will no longer move or slide smoothly between its open and closed positions with minimal effort. Thus it is desirable to have a high strength slat support retention and guide system which avoids metal on metal contact and protects the slats, side rails and retention system under all conditions.